Battery cassette

ABSTRACT

A battery cassette is disclosed. The battery cassette may include a frame including one or more hollow tubes. The battery cassette may further include a seal component having one or more hollow tubes aligned with the hollow tubes of the frame. The frame and the seal component may be configured to receive one or more battery cells in the hollow tubes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/906,931, filed Sep. 27, 2019, the disclosure of which is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

Embodiments of this disclosure relate to battery systems.

BACKGROUND

An electric vehicle (EV), also referred to as an electric drive vehicle,uses an electric motor for propulsion. Electric vehicles may includeall-electric vehicles where the electric motor is the sole source ofpower, and hybrid electric vehicles that include an auxiliary powersource in addition to the electric motor. In an electric vehicle, energymay be stored in a rechargeable battery system that includes multiplebattery cells to power the electric motor. The battery system typicallyincludes a plurality of battery packs that each include a plurality ofbattery modules. Each battery module includes multiple battery cells.Standard battery packs use fixed size modules to create battery packs.

Battery modules are the base building blocks of a battery pack. Abattery module includes multiple battery cells connected together inparallel and series. Typically, a battery module is not sub-dividableand is not easy to scale up or down in size. For example, existingbattery module designs include a fixed amount of battery cells andvoltages where changing either parameter would require major, structuralchanges. Further, current battery module designs may not adequatelyprotect their battery cells from neighboring cell side ruptures or fromexterior impacts. Moreover, existing battery modules may not protectbattery cells well against convective, conductive, and/or radiation heattransfer in the case of thermal runaway.

Embodiments of the current disclosure disclose battery cassettes thataddress some of the above-described limitations. In some embodiments,the disclosed battery cassette includes a protective frame for mountingbattery cells in a rigid assembly. The disclosed battery cassette mayinclude a seal to protect battery cells from hot gases and a hardplastic frame to protect battery cells from exterior damage/impacts. Insome embodiments, the disclosed battery cassette may include featuresthat allow multiple battery cassettes to easily connect in integernumbers to create larger/smaller battery modules. The scope of thecurrent disclosure, however, is defined by the attached claims, and notby the ability to solve any specific problem.

SUMMARY

Embodiments of the present disclosure relate to, among other things,battery systems for electric vehicles. Each of the embodiments disclosedherein may include one or more of the features described in connectionwith any of the other disclosed embodiments.

In one embodiment, a battery cassette is disclosed. The battery cassettemay include: a frame including one or more hollow tubes; and a sealcomponent having one or more hollow tubes aligned with the hollow tubesof the frame, wherein the frame and the seal component are configured toreceive one or more battery cells in the aligned hollow tubes of theframe and the seal component.

In another embodiment, a battery cassette is disclosed. The batterycassette may include: a frame including one or more hollow tubes; a sealcomponent having one or more hollow tubes aligned with the hollow tubesof the frame, the hollow tubes of the frame and the seal componentconfigured to receive one or more battery cells, wherein the batterycassette circumferentially surrounds each battery cell alongsubstantially an entire length of each battery cell.

In another embodiment, a battery cassette is disclosed. The batterycassette may include: a frame including one or more hollow tubes, theframe including a first material, wherein the hollow tubes areconfigured to receive one or more battery cells and the framecircumferentially surrounds each battery cell along substantially anentire length of each battery cell; a seal component having one or morehollow tubes aligned with the hollow tubes of the frame, the sealcomponent including a second material different than the first material,wherein the hollow tubes of the seal component are configured to securethe one or more battery cells in the battery cassette; a tongue locatedat a first end of the battery cassette, wherein the tongue is configuredto mate with a corresponding groove of a different battery cassette; anda groove located at a second end of the battery cassette, wherein thegroove is configured to mate with a corresponding tongue of thedifferent battery cassette.

In yet another embodiment, a battery cassette is disclosed. The batterycassette may include: a frame configured to support a plurality ofsimilarly oriented cylindrical battery cells therein, wherein anexternal surface of the frame includes, (a) one or more first matingfeatures configured to engage with corresponding mating features on theframe of a second battery cassette to removably couple the batterycassette to the second battery cassette, and (b) one or more secondmating features configured to engage with corresponding mating featureson an electrically conductive plate that is configured to electricallycouple the battery cassette to the second battery cassette.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of thepresent disclosure and together with the description, serve to explainthe principles of the disclosure. Each of the embodiments disclosedherein may include one or more of the features described in connectionwith any of the other disclosed embodiments.

FIG. 1A is a perspective view of an exemplary battery block havingbattery cassettes according to some embodiments of the presentdisclosure.

FIG. 1B is an exploded view of the battery block of FIG. 1A.

FIG. 2A is a perspective view of a single battery cassette isolated fromthe battery block of FIG. 1 .

FIG. 2B is an exploded view of the battery cassette of FIG. 2A.

FIGS. 3A-3F are different views of the battery cassette of FIG. 2A.

FIG. 4A is a cross-sectional view of a single tube of the batterycassette along line 4-4 in FIG. 3A.

FIG. 4B is an enlarged detailed view of a section of the batterycassette along line 4B of FIG. 4A.

FIGS. 5A-5B are different enlarged views of the battery cassette of FIG.2A.

FIG. 6A is a perspective view of the battery cassette of FIG. 2A withbattery cells mounted therein.

FIG. 6B is a bottom side view of the battery cassette of FIG. 6A.

FIGS. 7A-7C pictorially illustrate the method of assembling a batteryblock by building up an array of battery cassettes.

DETAILED DESCRIPTION

The present disclosure describes the battery cassette for a batterysystem of an electric vehicle. While principles of the currentdisclosure are described with reference to a battery cassette of anelectric vehicle, it should be understood that the disclosure is notlimited thereto. Rather, the battery cassettes of the present disclosuremay be used in any application (electric machine, electric tool,electric appliance, etc.). In this disclosure, relative terms, such as“about,” “substantially,” “slightly,” or “approximately” are used toindicate a possible variation of ±10% in the stated value. Anyimplementation described herein as exemplary is not to be construed aspreferred or advantageous over other implementations. Rather, the term“exemplary” is used in the sense of example or illustrative.

FIGS. 1A and 1B illustrate an exemplary battery block 102 havingcassettes 202 (“cassette 202”) according to one embodiment of thepresent disclosure. FIG. 1A shows a perspective view of battery block102, and FIG. 1B shows an exploded view. In the discussion that follows,reference will be made to both FIGS. 1A and 1B. Battery block 102 mayinclude multiple cassettes 202 (e.g., removably coupled) together. Eachcassette 202 may include a plurality of battery cells mounted therein.Battery block 102 may form a part of a battery system used in, forexample, an electric bus. Although an electric bus is referred toherein, battery block 102 (and cassette 202) may be included in anyelectric vehicle, energy storage device, or another application. In someembodiments, one or more battery blocks 102 may form a battery module ofthe battery system. Multiple battery modules (each including one or morebattery blocks 102 with multiple cassettes 202 coupled together) mayform a battery pack. The battery system (of the electric bus or otherapplication) may include multiple battery packs electrically connectedtogether to provide power. The multiple battery cells of battery block102 may be electrically connected together in parallel and/or in series.In some embodiments, the battery cells of one or more cassettes 202 (ofblock 102) may be electrically connected together in parallel to form aparallel-connected set (or brick) of battery cassettes. Battery block102 may include multiple such parallel-connected sets of batterycassettes. The multiple parallel-connected sets may be electricallyconnected together in series to form battery block 102. The batterycells may be rechargeable cylindrical battery cells having any chemistry(lithium-ion, nickel cadmium, etc.). As would be recognized by personsskilled in the art, packaging of cylindrical battery cells includeunique challenges that are not present in packaging other configurations(e.g., prismatic, pouch-type, etc.) battery cells.

Battery block 102 includes a positive exterior conductive plate (ECP)104, a negative ECP 106, one or more pairs of spanner ECPs 108A, 108B, acassette array 110 including one or more cassettes 202 containingbattery cells, one or more positive conductive foils 112, and one ormore negative conductive foils 114. As can be seen in FIG. 1B, thepositive and negative conductive plates 104, 106 may be a C-shapedcomponent that includes an end surface that contacts an end surface ofthe cassette array 110 and side surfaces (e.g., wedge-shaped surfaces inFIG. 1B) that contact a portion of the side surfaces of the array 110.In some embodiments, the positive and negative conductive plates 104,106 may be substantially similarly (or identically) shaped. The spannerECPs 108A, 108B may also be identically shaped and may contact portionsof the side surface of cassette array 110. In some embodiments, thepositive and negative conductive foils 112, 114 may be used toelectrically connect the battery cells of the one or more cassettes 202that form a parallel-connected set in parallel. And, the electricallyconductive plates may be used to connect the parallel-connected sets inseries. It is understood that the positive ECP 104, negative ECP 106,and spanner ECPs 108A, 108B may include any shape, size, and/or numberof components as desired.

As indicated in FIG. 1B, a pair of each spanner ECPs 108A, 108B may bepositioned on opposite side surfaces of the battery block 102. In thecontext of the current disclosure and for ease of explanation, thepositive exterior collective plate (ECP) 104, negative ECP 106, and theone or more pairs of spanner ECPs 108A, 108B will be collectivelyreferred to as the “exterior collector plates” or ECPs. ECPs may, ingeneral, be made of any electrically conductive material, such as, forexample, aluminum. As will be described later with reference to FIGS.5A-5B, cassettes 202 of block 102 may include features that engage withcorresponding features (slots, etc.) of the ECPs to attach the ECPs tothe block 102. Cassettes 202 may also include features that engage withcorresponding features of positive and negative electrically conductivefoils 112, 114 to attach these foils 112, 114 to the block 102. As willbe described in more detail later, the ECPs connect groups ofparallel-connected cassettes 202 of the cassette array 110 electricallyin series.

FIGS. 2A and 2B illustrate an exemplary cassette 202 isolated from thebattery block 102. FIG. 2A shows a perspective view of the cassette 202,and FIG. 2B shows an exploded view. Although not a requirement, asevident from these figures, in some embodiments, cassette 202 may beshaped generally like a rectangular prism. Cassette 202 may include atop end 10 and a bottom end 12 opposite the top end 10. Bottom end 12may be substantially parallel with top end 10. Cassette 202 may alsoinclude a first side 14, a second side 16 opposite first side 14, athird side 18, and a fourth side 20 opposite third side 18. First,second, third, and fourth sides 14, 16, 18, 20 may be substantiallyorthogonal (e.g., perpendicular) to both the top end 10 and bottom end12 and may each extend between top end 10 and bottom end 12. First andsecond sides 14, 16 may be substantially parallel to other, butsubstantially orthogonal to third and fourth sides 18, 20. Similarly,third and fourth sides 18, 20 may be substantially parallel to eachother, but substantially orthogonal to first and second sides 14, 16.Cassette 202 may include a length L, a width W, and a height H.

As shown in FIGS. 2A and 2B, cassette 202 may include a rigid frame 204and a seal component 206. Frame 204 may include a generally rectangular(or rectangular prism) shape having one or more hollow tubes 208. It isnoted that only one tube 208 is labelled in FIGS. 2A and 2B for clarity.The one or more tubes 208 may include a generally cylindrical shape andmay generally correspond to the external shape of battery cells 300 thatare positioned in tubes 208, as detailed below with reference to FIGS.6A and 6B. An outer surface of the tubes 208 may form first and secondside 14, 16 walls 209A, 209B of frame 204. Frame 204 may also includethird and fourth side 18, 20 walls 209C, 209D. As shown in FIG. 2B, insome embodiments, the third and fourth side 18, 20 walls 209C, 209D mayinclude a height H greater than a height of the tubes 208. For example,the third and fourth side 18, 20 walls 209C, 209D may extend beyond atop end 10 and/or a bottom end 12 of tubes 208. Accordingly, sealcomponent 206 may be mounted on a top end 10 of tubes 208 such that atop end 10 of seal component 206 is flush with a top end 10 of third andfourth side 18, 20 walls 209C, 209D. Frame 204 may also include one ormore ribs 211 for providing additional structural support. For example,ribs 211 may enable a reduction in material and weight of frame 204 (andthus, cassette 202), while maintaining structural integrity of frame204. Any number of ribs 211 may be included on frame 204 and the ribs211 may be located at any position on frame 204.

In some embodiments, frame 204 may include one or more plasticmaterials. The material of frame 204 may include, for example, thermosetplastics, thermoplastics, crystalline plastics, glass filled plastics,amorphous plastics, non-lubricated plastics, and/or any combinationthereof. In one embodiment, the material of frame 204 may includeglass-filled (GF), flame retardant (FR), non-conductive plastic. Forexample, frame 204 may include a crystalline plastic including glassfibers and metal hydroxides. Accordingly, the material of frame 204 maymaintain its form when exposed to high temperatures (e.g., when abattery cell 300 positioned in frame 204 experiences a thermal event orrupture). In some embodiments, the frame 204 may be made of one or moreamorphous or semi-crystalline thermoplastic materials (e.g., polyamide,polyphenylene oxide, polybutylene terephthalate, etc.). In someembodiments, the frame 204 may be made of a blend of multiplethermoplastic materials. The material makeup of frame 204 preferablyincludes low density, medium-high stiffness, high temperature,dimensionally accurate/stable, and/or medium-high surface energymaterials. It is understood that frame 204 may include any material asdesired, such as, but not limited to, metals, composites, fibers,ceramics, or any other material. In some embodiments, frame 204 may beopaque (e.g., black) to minimize or prevent radiant (e.g., infrared)heat transfer. For example, frame 204 may include a colored resin, suchas a black resin, to help reduce radiation heat transfer between thebattery cells and neighboring cells. However, it is understood thatframe 204 may also be substantially clear (e.g., transparent) and/or mayinclude any gradient of opaqueness and/or any color. As will bedescribed below, frame 204 may include features, such as one or moreapertures 210A, 210B, that engage with corresponding features (e.g.,flanges 214A, 214B) of seal component 206 to attach the seal component206 to frame 204.

Seal component 206 may include a shape generally corresponding to theshape of frame 204. For example, seal component 206 may include agenerally rectangular shape. Seal component 206 may include one or morehollow tubes 212 that may include a shape generally corresponding to theshape of tubes 208 of frame 204. It is noted that only one tube 212 islabelled in FIGS. 2A and 2B for clarity. Tubes 212 may include, forexample, a generally cylindrical shape for receiving battery cells 300,as detailed below. An outer surface of the tubes 212 may form first andsecond side 14, 16 walls 213A, 213B of seal component 206. Sealcomponent 206 may also include third and fourth side 18, 20 walls 213C,213D. Seal component 206 may be mounted on the top end 10 of tubes 208such that the top end 10 of seal component 206 is flush with a top end10 of third and fourth side 18, 20 walls 209C, 209D. Further, when sealcomponent 206 is mounted on frame 204, first and second side 18, 20walls 213A, 213B of seal component 206 may be flush with first andsecond side 18, 20 walls 209A, 209B of frame 204.

Seal component 206 may also include one or more features, such asflanges 214A, 214B that engage with the one or more apertures 210A, 210Bof frame 204. The flanges 214A and apertures 210A may be located on thefirst and second sides 14, 16 of cassette 202 (e.g., first and secondside 14, 16 walls 213A, 213B of seal component 206). Flanges 214B andapertures 210B may be located on the third and fourth sides 18, 20 ofcassette 202 (e.g., third and fourth side 18, 20 walls 213C, 213D ofseal component 206). Further, flanges 214A may include one or morecutouts 216 for engaging with one or more protrusions 218 of frame 204.The protrusions 218 may extend from frame 204 at a location adjacent tothe one or more apertures 210A. Accordingly, flanges 214A and cutouts216 may engage with apertures 210A and protrusions 218, and flanges 214Bmay engage with apertures 210B to mount seal component 206 to frame 204.

Seal component 206 may include any compliant material. In oneembodiment, the material of seal component 206 may be different than thematerial of frame 204. However, it is understood that the material ofseal component 206 may be the same as the material of frame 204. In someembodiments, seal component 206 may include one or more materials, suchas elastomers, that can maintain structural integrity in hightemperatures and include a low density. In some embodiments, thematerial of seal component 206 may include, for example, rubbers,thermoplastic elastomers, thermoplastic copolyesters, or any otherelastomer material, and/or combinations thereof. In some embodiments,seal component 206 may include liquid silicone rubber, thermoplasticcopolyesters (TPE-C), and/or another high temperature elastomer. Suchmaterials may help to prevent, or reduce, convective heat transferbetween the battery cells and seal component 206. Seal component 206 mayfurther include flame retardant materials, such as metal hydroxides orthe like. The material used for seal component 206 may have any density(and other material properties). In some embodiments, the density of thematerial of seal component 206 may be in the range of 0.8 g/cm³ to 2.00g/cm³, for example, 1.21 g/cm³. However, as explained above, in general,the material of seal component 206 may have any density as desired. Thematerial of seal component 206 may include materials that include hightemperature resistance, amorphous, thermoset, low density materials. Forexample, the material of seal component 206 may maintain structuralintegrity when exposed to temperatures of at least 200 degrees Celsiusor greater. In some embodiments, seal component 206 may be opaque forprevention of radiation (e.g., infrared) heat transfer. For example,seal component 206 may include a colored resin, such as a black resin,to help reduce radiation heat transfer between the battery cells andseal component 206. However, it is understood that seal component 206may also be substantially clear (e.g., transparent) and/or may includeany gradient of opaqueness and/or any color.

Cassette 202 may be manufactured or formed through molding, casting,machining, joining, or any other manufacturing process (e.g., 3Dprinting). Frame 204 may be manufactured by, for example, injectionmolding, or the like. Further, seal component 206 may be manufactured byinjection molding, compression molding, or the like. In someembodiments, frame 204 and seal component 206 may be formed byovermolding. As used herein, overmolding is a process in which a singlepart (e.g., cassette 202) is created using two or more differentmaterials in combination. Overmolding may include a first material, suchas the material of frame 204, being partially or fully covered by asecond material, such as the material of seal component 206 during themanufacturing process. Accordingly, overmolding may enable sealcomponent 206 to bond to frame 204. Additionally, or alternatively, anadhesive bond, such as epoxy or the like, may be used to bond sealcomponent 206 to frame 204. Thus, cassette 202 may include a two-piececonstruction (e.g., frame 204 and seal component 206) for securingbattery cells 300, as detailed further below. In some embodiments, frame204 and seal component 206 may be manufactured together as a singlecomponent such that cassette 202 includes a single component.

The side walls 209A, 209B, 209C, 209D of frame 204 and the side walls213A, 213B, 213C, 213D of seal component 206 may define the length L,height H, and width W of cassette 202. For example, a length of sidewalls 209A, 209B including a length of side walls 209C, 209D may definethe overall length L of cassette 202. The length L is defined by thenumber of tubes 208, 212 included on cassette 202. Further, a height andwidth of side walls 209C, 209D may define the overall height H and widthW of cassette 202, respectively. The dimensions (L×H×W) of cassette 202may correspond to an overall size of the battery modules and may bechosen accordingly. In one embodiment, the length L may be 145.65 mm(5.73 in), the height H may be 73.25 mm (2.88 in), including protrusions502B, or 69.75 mm (2.746 in) when protrusions 502B are not included, andthe width W may be 40.7 mm (1.602 in). However, the dimensions ofcassette 202 may include a range of dimensions. For example, the lengthL may be in a range from 21.5 mm (0.846 in) to 1000 mm (39.370 in). Theheight H may be in a range from 11 mm (0.433 in) to a total height ofbattery cells 300, for example, 69.75 mm (2.746 in). The width W may bein a range from 21.5 mm (0.846 in) (e.g., when only a single row 220A oftubes 208, 212 is included) to 1000 mm (39.370 in). Further, an overallweight of cassette 202 may be 0.097 kg (0.214 lbs). However, the weightof cassette 202 may be in a range from 0.04 kg (0.0881 lbs) to 0.3 kg(0.661 lbs). It is understood that cassette 202 may include any size,dimensions, and/or weight, as desired.

FIG. 3A is a top end 10 view of an exemplary embodiment of cassette 202of FIG. 2A. FIG. 3B is a bottom end 12 view of the exemplary cassette202 of FIG. 2A. As shown in FIGS. 3A and 3B, in some embodiments,cassette 202 may include twelve hollow tubes 208, 212. For example,frame 204 may include twelve tubes 208 and seal component 206 mayinclude twelve tubes 212, accordingly. The tubes 208, 212 may be alignedin one or more rows. For example, cassette 202 may include a first row220A and a second row 220B of tubes 208, 212. Each row 220A, 220B mayinclude six tubes 208, 212. The rows 220A, 220B may be offset such thatthe tubes 208, 212 of the adjacent rows 220A, 220B are not alignedperpendicularly. Accordingly, the tubes 208, 212 may be tightly nestedto enable a greater number of tubes 208, 212 while minimizing an overallsize of cassette 202. It is understood that cassette 202 may include anynumber of tubes 208, 212 and any number of rows 220A, 220B as desired.Further, frame 204 may include a thickness t1 between tubes 208. Thethickness t1 between tubes 208 of frame 204 may be defined by a distancebetween tubes 208. In one embodiment, the thickness t1 may be less than1 mm (0.0394 in), and preferably may be 0.80 mm (0.0315 in). As detailedbelow, an inner diameter of tubes 208 may taper from the top end 10 tothe bottom end 12. Accordingly, the thickness t1 between tubes 208 mayvary from the top end 10 to the bottom end 12. Thus, the thickness t1may be in a range from 0.25 mm (0.00984 in) at the top end 10 to 0.8 mm(0.0315 in) at the bottom end 12.

FIG. 4A is a cross-sectional view of a single tube 208, 212 along line4-4 of the cassette 202 of FIG. 3A. FIG. 4B is a detailed view of thecircled portion of the single tube 208, 212 of FIG. 4A. As shown inFIGS. 4A and 4B, tube 208 of frame 212 may include a varying innerdiameter. For example, tube 208 may include a first diameter d1 and asecond diameter d2. In some embodiments, diameter d1 may be greater thanthe diameter d2. In some embodiments, the inner diameter of tube 208 offrame 204 may taper from the top end 10 (e.g., from diameter d2) to thebottom end 12 (e.g., diameter d1) along a length of tube 208 such thatthe inner diameter of tube 208 varies from the top end 10 towards thebottom end 12. Diameter d2 may be slightly larger than, slightly smallerthan, or substantially equal to, a diameter d5 of battery cells 300, asdetailed further below. In one embodiment, diameter d1 may be 21.46 mm(0.845 in) and diameter d2 may be 21 mm (0.827 in). It is understoodthat diameter d1 and diameter d2 may be any size and/or dimension asdesired.

Tube 212 of seal component 202 may include a third inner diameter d3.Diameter d3 may be the same, or substantially similar, to diameter d2 oftube 208. For example, diameter d3 may be 21 mm (0.827 in). In someembodiments, the inner diameter of tube 212 may be substantiallyconstant along a length of tube 212. However, in some embodiments, theinner diameter of tube 212 may taper along the length of tube 212. Asbest seen in FIG. 4B, tube 212 of seal component 206 may include acircumferential lip or protrusion 222 that protrudes from a sidewall ofthe tube 212 into the tube cavity. The protrusion 222 may extend aroundan inner circumference of tube 212 such that the protrusion 222 isinternal of seal component 206. Protrusion 222 may extend radially infrom a radially inner wall of tube 212 such that tube 212 may include afourth inner diameter d4. Diameter d4 may be less than diameter d3and/or diameter d2. In one embodiment, diameter d4 may be 20.1 mm (0.791in). The protrusion 222 may correspond to a groove 302 (shown in FIG.7A) on the cylindrical sidewall of battery cell 300 such that the groove302 of battery cell 300 receives protrusion 222 when battery cell 300 ismounted in tubes 208, 212, as detailed further below. In someembodiments, tubes 212 of seal component 206 may include acircumferential lip or protrusion (not shown) at the top end 10 (e.g.,located longitudinally above protrusion 222) to thermally andelectrically insulate a shoulder of battery cell 300, while alsoproviding a location stop during battery cell 300 installation. Forexample, the circumferential lip of each tube 212 may be at, oradjacent, a top end 10 surface of seal component 206 and may extendradially in from the radially inner wall of tube 212. Accordingly, thecircumferential lip may radially cover a portion of battery cell 300.The circumferential lip at the top end 10 may enable use of unwrappedcylindrical battery cells 300 by provided additional thermal andelectrical insulation.

FIG. 6A shows a perspective view of cassette 202 with battery cells 300mounted therein. FIG. 6B shows a bottom end 12 view of the cassette 202with a detailed view of the battery cells 300 mounted therein. As shownin FIG. 6B, battery cells 300 may include an outer diameter d5. Diameterd5 may be smaller than diameter d1 and diameter d2 and may be largerthan diameter d3 and diameter d4. Accordingly, battery cells 300 can beinserted into cassette 202, as detailed below with respect to FIG. 5A.In one embodiment, diameter d5 may be, for example, 21.1 mm (0.831 in).It is understood that any type of battery cell 300 may be used thatincludes any size, shape, and/or voltage as desired. In someembodiments, the maximum diameter of the battery cell 300 may beslightly larger than the inner diameter of the plastic tube at the topend (d3), e.g., if the tolerances of the parts stack worst case.However, typically, the maximum diameter of the battery cell 300 isslightly smaller than the inner diameter of the plastic tube at the topend.

Each battery cell 300 includes a current interrupt device (CID)positioned inside its casing proximate its positive terminal. The CID istypically employed to provide protection against any excessive internalpressure increase in the battery cell by interrupting the current pathfrom the battery cell when pressure inside its casing is greater than apredetermined value. The CID typically includes first and secondconductive plates in electrical communication with each other. The firstand second conductive plates are, in turn, in electrical communicationwith an electrode and a terminal of the battery cell, respectively. Thesecond conductive plate separates from (e.g., deforms away or isdetached from) the first conductive plate of the CID when pressureinside the battery is greater than a predetermined value, whereby acurrent flow between the electrode and the terminal is interrupted. Thegap between the first and second conductive plates also allows the highpressure gases from inside the casing of the battery cell to vent orescape to the outside. In some cases, the first and second conductiveplates of the CID are formed of different materials that expanddifferently when heated to cause the two plates to separate from eachother. For example, when the temperature of the battery cell exceeds athreshold (for example, due to a defect in the battery cell), thebi-metallic conductive plates of the CID deflects or bends (e.g., due todifferent thermal expansions of the materials of the bi-metallic disc)and cuts the battery cell off from the circuit.

When mounted in cassette 202, battery cells 300 may be flush with thetop end 10 of seal component 206 at a positive terminal 300A end ofbattery cell 300. Frame 204 may circumferentially surround each batterycell 300. Further, battery cell 300 may extend beyond the bottom end 12of frame 204 at a negative terminal 300B end of battery cell 300. Assuch, cassette 202 may circumferentially surround each battery cell 300along substantially an entire length of each battery cell 300. Thegroove 302 (FIG. 7A) of battery cells 300 may receive protrusion 222 ofseal component 206 such that seal component 206 may secure battery cells300 in cassette 202. Further, battery cells 300 may be secured incassette 202 by an interference fit with tubes 212 of seal component 202due to outer diameter d5 of battery cells 300 being smaller than innerdiameter d3 of tube 212. The seal component 206 also allows the cells300 to vent via their CID proximate the positive charge end 300A.

As further shown in FIG. 6B, a circumferential gap 224 may be formedbetween battery cell 300 and tube 208 of frame 204 when battery cells300 are mounted in cassette 202. The circumferential gap 224 may beformed due to outer diameter d5 of battery cells 300 being smaller thaninner diameter d1 of tubes 208. Accordingly, due to the differencebetween outer diameter d5 and inner diameter d1, battery cells 300 maybe inserted into cassette 202 from the bottom end 12 of cassette 202.The circumferential gap 224 may also allow a column of air between frame204 and cells 300 to help prevent conductive heat transfer between thecells 300 and frame 204.

FIG. 3C is a first side 14 view of cassette 202, FIG. 3D is a secondside 16 view of cassette 202, FIG. 3E is a third side 18 view ofcassette 202, and FIG. 3F is a fourth side 20 view of cassette 202. Asshown in FIGS. 3C-3F, cassette 202 may include one or more matingfeatures, such as a tongue 402A, 402B and groove 404A, 404Bconfiguration, for mating multiple cassettes 202 together, as detailedfurther below with respect to FIGS. 7A-7C. For example, first side 14 ofcassette 202 may include a first tongue 402A and a first groove 404Alocated on frame 204. Tongue 402A may be located at a first end (e.g.,at third side 18) of frame 204 and groove 404A may be located at asecond opposite end (e.g., at fourth side 20) of frame 204 on the firstside 14. Second side 16 of cassette 202 may include a second tongue 402Band a second groove 404B located on frame 204. Tongue 402B may belocated at the second end (e.g., at fourth side 20) of frame 204 andgroove 404B may be located at the first end (e.g., at third side 18) offrame 204 on the second side 16.

As shown in FIGS. 3C and 3D, tongues 402A, 402B and grooves 404A, 404Bmay extend substantially an entire height H of cassette 202 (e.g., frame204 of cassette 202). Tongue 402A may include a shape corresponding to ashape of groove 404B such that tongue 402A may be fitted (e.g., slid)into groove 404B of another cassette 202. Likewise, tongue 402B mayinclude a shape corresponding to a shape of groove 404A such that tongue402B may be fitted (e.g., slid) into groove 404A of another cassette202.

Tongues 402A, 402B and grooves 404A, 404B may be oriented such thattongues 402A, 402B may slide (e.g., mate) into grooves 404A, 404B. Forexample, tongue 402A may be oriented in a first direction and groove404B may be oriented in the first direction such that the bottom end 12of tongue 402A may slide into the top end 10 of groove 404B. Likewise,tongue 402B may be oriented in a second direction and groove 404A may beoriented in the second direction such that the top end 10 of tongue 402Bmay slide into the bottom end 12 of groove 404A. Accordingly, tongue402A and groove 404A of cassette 202 may slide onto and mate with tongue402B and groove 404B of an adjacent cassette 202 to removably couple thetwo cassettes together.

As shown in FIGS. 3A-3D, cassette 202 may also include mating and datumfeatures 405 at an end of the tongue 402A, 402B and groove 404A, 404Bfeatures to control tolerance stack of the block 102. For example, thedatum features 405A, 405B may include 2-way datum and/or a 4-way datum.As used herein, a 2-way datum is a datum feature 405 that restrictsmovement along one (1) axis (i.e., in two directions along one axis).Further, a 4-way datum is a datum feature 405 that restricts movementalong two (2) axes. The datum features 405 may include, for example, apin 405A and a corresponding hole 405B for receiving the pin 405A. Thehole 405B may include a shape corresponding to a shape of the pin 405A.For example, the pin 405A may include a generally cylindrical shape andthe hole 405B may include a generally circular shape. The pins 405A maybe located on tongues 402A, 402B, respectively, and the holes 405B maybe located in grooves 404A, 404B, respectively.

As further shown in FIGS. 3C-3F, cassette 202 may also include one ormore snap-fit features for locking cassettes 202 together after twocassettes 202 have been mated. The snap-fit features may include a malesnap components 406A and female snap components 406B. Male snapcomponents 406A may include one or more protrusions that correspond to asnap-in area of the female snap components 406B. Accordingly, the femalesnap components 406B may receive the male snap components 406A and lock,or restrict, the male snap components 406A in place. The snap featuresmay also include a lever 408, or pin, for undoing the snap-fit of themale and female snap components 406A, 406B. For example, the lever 408may be pushed such that the male component 406A is no longer restrictedby the female component 406B. When the lever 408 is pushed, the malecomponent 406A may be moved beyond the female component 406B to undo thesnap-fit. While the exemplary embodiments of the mating featuresdescribed herein include tongue and groove and snap-fit features, it isunderstood that the mating features may include any type of matingfeature for mating two or more components together. For example, themating features may include one or more fasteners (e.g., bolts, screws,etc.), adhesive, or the like. Further, the mating features may belocated on any side 10, 12, 14, 16, 28, 20 of cassette 202 and in anylocation, and may include any number and/or combination of matingfeatures.

FIG. 5A shows an enlarged perspective view of a portion of the top end10 of cassette 202. FIG. 5B shows an enlarged perspective view of aportion of the bottom end 12 of cassette 202. With reference to FIGS.2A-2B, 3A-3F, and 5A-5B, cassette 202 may further include features toattach to the positive and negative conductive foils and/or the ECPs toform block 102. In some embodiments, the features may include keying,alignment and locking features 502A, 502B, 502C, etc. on the frame 204of cassette 202 that engage with corresponding features (slots, etc.) onECPs and/or the foils to couple the ECPs and/or the foils to thecassette array. For example, features 502A and 502B may includeprotrusions, or pins, on cassette 202 (e.g., on frame 204 of cassette202) that may engage with (or fit into) slots or cavities in the ECPsand/or the foils to couple the ECPs and/or the foils to the cassettearray. These protrusions and slots may be configured or shaped such thatthe ECPs and/or the foils are oriented in the desired manner on cassettearray. Further, features 502C may include a snap-fit feature thatincludes a male component for engaging with a corresponding slot of theECPs and/or foils. Accordingly, the ECPs and/or foils may be secured tothe cassette array 110.

In one embodiment, protrusions 502A and snap feature 502C may be locatedon the third side 18 and fourth side 20 of frame 204. For example, eachside 18, 20 may include two (2) protrusions 502A and two (2) snaps 502C.A first protrusion 502A and a first snap 502C may be located at a topend 10 of each side 18, 20 and a second protrusion 502A and a secondsnap 502C may be located at a bottom end 12 of each side 18, 20.Further, protrusions 502B may be located on a top end 10 and a bottomend 12 of frame 204. For example, a first protrusion 502B and a secondprotrusion 502B may be located on top and bottom ends 10, 12,respectively, at third side 18. Likewise, a third protrusion 502B andfourth protrusion 502B may be located on top and bottom ends 10, 12,respectively, at fourth side 20. It is understood that cassette 202 mayinclude any number and arrangement of features 502A-502C and features502A-502C may be located at any location on frame 204 and/or sealcomponent 206.

FIGS. 7A-7C depict the assembly of the exemplary battery cassette array110 of block 102 (see FIG. 1B) according to some embodiments. As notedabove, battery cassette array 110 may include one or more batterycassettes 202 coupled together. FIG. 7A depicts a plurality of batterycells 300 being inserted into the exemplary cassette 202. For example,the battery cells 300 may be inserted into tubes 208, 212 from thebottom end 12 of cassette 202. When inserted and mounted, the batterycells 300 are oriented such that the positive terminal 300A of eachbattery cell 300 is aligned in the same direction. Accordingly, thenegative terminal 300B of the battery cells 300 are also aligned in thesame direction. The aligned battery cells 300 are then inserted intocassette 202 (e.g., frame 204 of cassette 202) to securely hold thebattery cells 300 in place and form a cassette 202.

FIG. 7B shows two cassettes 202A, 202B being coupled together, accordingto an embodiment of the present disclosure. As shown in FIGS. 2A-2B and7B, the exterior surface of the cassettes 202A, 202B are contoured, orinclude features, to enable one cassette 202A to mate, engage, andcouple with (e.g., removably couple with) another cassette 202B. Forexample, the exterior surface of the frame 204 and seal component 206 ofone cassette 202A may include grooves, or other features, thatcorrespond with features on the exterior surface of frame 204 and sealcomponent 206 of a second cassette 202B. These mating features allow thetwo cassettes 202A, 202B to align and couple with each other such that abattery block 102 (see FIG. 7C) is formed with the battery cells 300 inthe cassettes 202 oriented and aligned as desired. In some embodiments,the cassettes 202A, 202B slide together in the tongue 402A, 402B andgroove 404A, 404B configuration with snap-fit final engagement, asdetailed above. For example, tongue 402A of cassette 202B may be slidinto groove 404B of cassette 202A. Likewise, groove 404A of cassette202B may be slid into tongue 402B of cassette 202A. The cassettes 202A,202B are removably coupled to each other such that they can be coupledto each other and separated from each other using their matingengagement features. Multiple cassettes 202 are joined together in asimilar manner to form battery cassette array 110, as shown in FIG. 7C.In the embodiment illustrated in FIG. 7C, ten (10) cassettes 202, withtwelve (12) battery cells 300 each, are joined together to form cassettearray 110. However, this is only exemplary. In general, a cassette 202may support any number of battery cells 300, and any number of cassettes202 may be coupled together (as described above) to form blocks 102 withdifferent energy capacities. Adding additional cassettes 202 to array110 increases the energy capacity of the cassette array 110. The voltageoutput (and consequently the current output) of a cassette array 110 canalso be varied independent of its energy capacity by changing the numberof cassettes 202 that are connected together in parallel, and the numberof parallel-connected cassettes 202 connected together in series.

As can be seen in FIG. 7C, the positive terminal 300A of each batterycell 300 of block 110 is oriented in the same direction thus enablingthe opposite negative terminal 300B (not seen in FIG. 7C) of the cells300 to contact a cooling plate (not shown). The ability to easily add onmultiple cassettes 202 to form battery cassette array 110 (and addadditional cassettes 202 to the array 110 to extend the block 102)enables the energy and voltage of a battery module (formed from block102) to be scaled in a flexible manner. After the cassette array 110with the desired number of cassettes 202 is formed, a block 102 (seeFIGS. 1A and 1B) may be formed by assembling the positive and negativeconductive foils 112, 114 and the ECPs 104, 106, 108A, 108B, etc. withthe cassette array 110. The number of ECPs, specifically the number ofinner spanner ECPs 108A, 108B, etc. may be adjusted according to thenumber of cassettes 202 included in the battery block 110 and thedesired energy and voltage.

As shown in the embodiments above, the voltage and energy provided bythe battery blocks 110 may be independently scaled as desired. Forexample, the voltage provided by the battery block 110 shown in FIG. 1Amay be scaled from 12V to 36V simply by providing a differentconfiguration for ECPs (and foils). Further, the positive and negativefoils may be provided based on the configuration of ECPs. As is wellknown, more battery cells indicate more energy. As such, if a certainvoltage is required, yet a high level of energy is not necessary,several cassettes 202 may be removed from the battery block 110. In suchinstances, the appropriate exterior collector plates, in addition to theappropriate positive and negative foils, may be applied to the obtainedbattery cassette array 110 for required voltage at the desired energylevel. Thus, with the described architecture, the battery modules andbattery packs are both scalable in voltage and energy independently.Being able to scale at both levels (voltage and energy) allows for thebattery pack size to be tailored to the application and available spacein the chassis for mounting batteries.

The ability to scale the battery pack and battery module independentlyfor energy and voltage allows for the pack size to be more easilytailored to the application and available space in the chassis formounting batteries. For example, while a heavy duty vehicle (such as abus) may need a battery pack with a low output voltage relative to theenergy storage needs (to provide the required range), a lighter vehicle(e.g., a light truck, car, etc.) may need a battery pack with a higheroutput voltage relative to the energy storage needs to meet the requiredrange. The disclosed cassette 202 can enable these differentapplications by sub-dividing the battery module (using different ECPsand foils) into different number and size of bricks (i.e., the number ofcassettes 202 that are connected together in parallel) to provide theneeded voltage. The ability to easily reconfigure a battery pack fordifferent applications using the same base building blocks increasesoperational and engineering efficiency while reducing time to market andsaving money on validation and capital equipment costs.

Further, the cassette 202 of the present disclosure may enable thebattery cells 300 to be safely packaged together. For example, the tubes208 of frame 204 may provide separation between adjacent battery cells300. Accordingly, if a battery cell 300 experiences a thermal runawayevent, ruptures, or otherwise fails, frame 204 may provide protection tothe other battery cells 300 to help prevent the damage from spreadingand causing other battery cells 300 in the cassette 202 from failing.The tubes 208 of frame 204 may provide separation between adjacentbattery cells 300. The materials, colors, and design of frame 204 andseal component 206 may also help prevent, or otherwise reduce,conductive, convective, and/or radiation heat transfer. For example, thegap 222 between tubes 208 of frame 204 and the battery cells 300 mayallow a thermally-insulating column of air for preventing or reducingconduction heat transfer. The seal component 206 (e.g., silicone orother elastomers) may help to prevent or reduce convective heat transferby forming a gas-tight seal with battery cells 300. Further, opaquematerials of the frame 204 and/or the seal component 206 may help toprevent or reduce radiation heat transfer.

A number of features of cassette 202 may also help to reduce overallsize and weight of cassette 202. For example, ribs 211 may enable lessmaterial to be used while maintaining structural support of cassette202. Further, material selection (e.g., thermoplastics and elastomers)may also help to reduce weight.

While principles of the present disclosure are described herein withreference to an exemplary design of a cassette 202, a person of ordinaryskill in the art would readily recognize that many variations can bemade to the design of the cassette 202. For example, the cassettes ofthe current disclosure may support any number and type of battery cells.Any number of cassettes 202 may be coupled together to form a batterymodule. And, any type of mating features may be used to couple adjacentcassettes 202 together. Further, although the battery system of anelectric bus is described, it should be understood that the disclosureis not limited thereto. Rather, the systems described herein may beemployed in the batteries of any application. Also, those havingordinary skill in the art and access to the teachings provided hereinwill recognize additional modifications, applications, embodiments, andsubstitution of equivalents all fall within the scope of the embodimentsdescribed herein. Accordingly, the disclosure is not to be considered aslimited by the foregoing description. For example, while certainfeatures have been described in connection with various embodiments, itis to be understood that any feature described in conjunction with anyembodiment disclosed herein may be used with any other embodimentdisclosed herein.

We claim:
 1. A battery cassette, comprising: a frame including one ormore hollow tubes; and a seal component having one or more hollow tubesaligned with the hollow tubes of the frame, wherein the frame and theseal component are configured to receive one or more battery cells inthe aligned hollow tubes of the frame and the seal component; wherein amaterial of the frame is different than a material of the sealcomponent, and wherein the frame includes a rigid material and the sealcomponent includes a compliant material.
 2. The battery cassette ofclaim 1, wherein the seal component is configured to secure the batterycells in the battery cassette.
 3. The battery cassette of claim 2,wherein each hollow tube of the seal component include an internalcircumferential protrusion that is configured to engage with a matingrecess in a battery cell.
 4. The battery cassette of claim 1, whereineach hollow tube of the frame circumferentially surrounds a respectivebattery cell.
 5. The battery cassette of claim 1, wherein each hollowtube of the frame is configured such that a circumferential air-gap isformed between an inner wall of the tube and an outer wall of a batterycell when the battery cell is received in the hollow tube.
 6. Thebattery cassette of claim 1, wherein the rigid material is athermoplastic.
 7. The battery cassette of claim 1, wherein the frame andthe seal component are formed by a molding process, and wherein theframe and the seal component are formed by overmolding.
 8. The batterycassette of claim 1, further comprising one or more mating features formating two or more battery cassettes together.
 9. The battery cassetteof claim 8, wherein the one or more mating features include one or moretongues and one or more grooves.
 10. The battery cassette of claim 9,wherein the tongues and grooves include snap-fit features.
 11. Thebattery cassette of claim 1, further including one or more protrusionslocated on a side and/or an end of the battery cassette.
 12. The batterycassette of claim 1, further including one or more snap-fit featureslocated on a side and/or an end of the battery cassette.
 13. A batterycassette, comprising: a frame including one or more hollow tubes; and aseal component having one or more hollow tubes aligned with the hollowtubes of the frame, wherein the frame and the seal component areconfigured to receive one or more battery cells in the aligned hollowtubes of the frame and the seal component; wherein the frame includes aflame-retardant material and/or glass fibers, and wherein the sealcomponent includes a thermoplastic elastomer.
 14. A battery cassette,comprising: a frame including one or more hollow tubes; and a sealcomponent having one or more hollow tubes aligned with the hollow tubesof the frame, wherein the frame and the seal component are configured toreceive one or more battery cells in the aligned hollow tubes of theframe and the seal component; one or more mating features for mating twoor more battery cassettes together, wherein the one or more matingfeatures include one or more tongues and one or more grooves, whereinthe tongues and grooves extend substantially an entire height of thebattery cassette.
 15. A battery cassette, comprising: a frame includingone or more hollow tubes; a seal component having one or more hollowtubes aligned with the hollow tubes of the frame, the hollow tubes ofthe frame and the seal component configured to receive one or morebattery cells, wherein the battery cassette circumferentially surroundseach battery cell along substantially an entire length of each batterycell wherein the frame includes a rigid material and the seal componentincludes a compliant material.
 16. The battery cassette of claim 15,wherein the frame and the seal component each include at least two rowsof hollow tubes, and wherein the rows of hollow tubes are offset fromeach other.
 17. A battery cassette, comprising: a frame configured tosupport a plurality of similarly oriented cylindrical battery cellstherein, wherein an external surface of the frame includes, (a) one ormore first mating features configured to engage with correspondingmating features on a frame of a second battery cassette to removablycouple the battery cassette to the second battery cassette, and (b) oneor more second mating features configured to engage with correspondingmating features on an electrically conductive plate that is configuredto electrically couple the battery cassette to the second batterycassette; wherein the one or more first and/or second mating featuresinclude one or more tongues and one or more grooves; wherein the tonguesand grooves extend substantially an entire height of the batterycassette.
 18. The battery cassette of claim 17, wherein the one or morefirst mating features of the battery cassette include the one or moretongues configured to engage with a correspondingly shaped one or moregrooves of the second battery cassette.
 19. The battery cassette ofclaim 17, wherein the frame includes a plurality of hollow tubes thatextend from a top surface of the frame to a bottom surface of the frame,wherein each hollow tube of the plurality of hollow tubes is configuredto receive a battery cell therein.